Abstract Neuroergonomics is an emerging field that investigates the human brain in relation to behavioral performance in natural environments and everyday settings. Neuroergonomics research aims to expand our understanding of the neural mechanisms underlying human perceptual, cognitive, and motor functioning with a focus on real-world contexts. Traditional neuroimaging devices such as Functional Magnetic Resonance Imaging (fMRI) can be expensive, impractical, and ill-suited for large scale deployment to explore, utilize and further understand complex motor tasks, particularly within communities of disability. Therefore, functional Near Infrared Spectroscopy (fNIRS), an emerging wearable neuroimaging technique that measures the similar cortical hemodynamic response as in fMRI but with portable, more accessible and relatively low cost sensors, offers a unique opportunity to explore the cognitive function out of the laboratory, including wheelchair control. Cognitive workload refers to the task demands on the limited processing capacity of the brain. Often when an individual?s processing capacity reaches its limit, performance breakdown and errors will occur. Among people with disabilities, performance errors can lead to serious injury, behavioral change, and impact equality and autonomy. Complementary approaches to accessibility involve new generation assistive device interfaces, including power- assist features, which can provide reductions in cognitive and physical workload, for improved safety, autonomy, social-wellness, and quality of life. However, currently much of our understanding of cognitive and physical workload is limited to subjective assessments in the context of wheelchair control. This proposal is the first of its kind, using new generation ultra-portable brain monitoring sensors to explore and understand the cognitive workload interactions of the individual and the environment during active wheelchair control, ultimately leading to the development of unique methodology and objective assessments of currently accepted standards and mobility devices. Aim 1 will incorporate portable brain and body measurements (cortical hemodynamic oxygenation changes with fNIRS, heart rate with ECG, body movement with a central accelerometer), and self-reported assessments to evaluate mental and physical effort during active wheelchair control within American Disability Association regulated environments. We expand further in Aim 2, where we will assess the neuroergonomic design of Power-Assisted Devices, in order to characterize how complementary mobility interfaces can impact user experience and environmental engagement. This study will develop a framework for a comprehensive analysis of user?s cognitive, affective and physical interaction for future assistive devices to improve personalization, mobility, and rehabilitation. This study will contribute to understanding the operator-environmental-machine interactions on mental workload of differently-abled users. Furthermore, it will provide a new approach to objectively assess operator interactions for the research and development of current and new mobility devices.